SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74faf88645ea0f0593f1f9c530e2d22b2b6c6e54980b30f26cd83f8293e77aa3' 
  AND token = 'BKPO+0QjyWfj2XeZ6LpfPUWYRMgiywXF6u/KtlQV8wQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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