SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '26f21a8df934141aee7482cacef35a22fb6561fc3c3b0095a0da2abd1cc7d959' 
  AND token = 'l4kz2UTsEfNGtm6v7+lAiIraAit33B7h7RK5k1LPg1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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