SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f1df97c05d86e2b46af5b897bd4d7e95005fac4083da67e440bb622aefcd0b63' 
  AND token = 'xaENRIDrgULF1oG4S+Kb5ij62vweqhB+IVzJVqW78lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}