SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d7041c2d787853074e04ac969f9682bec44419a08fb93a5d7c4c7f77edae429' 
  AND token = 'Lb+5oVQrol/0nEE5qAWKqIGv3lJGDFKZojPE5amyEdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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