SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0498cda65d24407dc7123e973bee09c50075c3925dd91dba085a09026982df10' 
  AND token = 'xD4AXw8TARsBtXFllr1KckGXoOZ1FEKR6njiaL5cXoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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