SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78025d31c23a494f03bf00da6c2f15b978019f18f79114df0bee618dee37da6c' 
  AND token = '5jnOF3Nr/NXxPsY2GpJ42t+V6JuVllYdq7Uc7GlfxvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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