SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '427125f6e1e0168aad8d82ad039eecd1e35535f246b59a63590a9f4184dc48c6' 
  AND token = 'oiSfURVpeMM0UfmsaZuMmrqLKGlKdpbCuC99zQvQO38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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