SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c530b73b73c56a6402175525c0315fe16b41360a1173ac3be808d10d92962fe' 
  AND token = 'Lb6Frg8Zn/Kitwh2AhIdRz3fojkVNWAXWEkkTLwYNc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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