SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dde0cfbfa79db2a1d82406aa26a500a97a9b0507ec662a7ef57446d31b480215' 
  AND token = 'iKFeT2e8JXBRF7tPDFDvWWH3zLYEFix7QgkZ4TeDrGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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