SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2b9a9cbf55ae837eecc6d56a71a329cd0dcab73372835f0ab4b4b710b100cb0' 
  AND token = '+yrR7UheUNnPwwF1Qq1n3Zf9rCHfCapPtapftixfj/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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