SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f2cb4350de51fd7904c39a6686cf069ff2f1e96dcec75b6835046fa401c1e5e4' 
  AND token = 'X+38LRvar1ujCsDKt0dwduziSihRhreLzBoOl9ttGjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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