SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fb8d4e7ee8b400d985ae8e084a2a56750c69e2378b1ca9c502a3631f3e0b0e53' 
  AND token = 'bpmc7pENmXj0mUp6Nw2H6Bfk5VJ6xGltId/Zd+ZXHA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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