SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b2c43b4fd67622014ef78619a9aed5f5cd47c3c6d5b15e486112eff73be476' 
  AND token = 'UFJiswzrjPNA5+jh/AcpwkUlkpAVOCNn6cbLjYYFna4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}