SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e44a5a9b9bf438efaef5a46c70fc6371133632a00ff813a4db1aa1e9c78586c3' 
  AND token = 'fNiICtWVELJqsuGPK2EtJwspDTJ68hj3g+l0nzpmD8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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