SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f1df7b8806bae605300835aa31da2ae42af397198f688cd9b4788dc63dd36c2' 
  AND token = 'oUBFz/lVcRH/y5AJFRsooMR7+KZoKSBQ4HNhlLssq2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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