SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c9dd6a844e246920c6b7af6d5898404bc5348cb0cefc394da77c9c0eb659c5' 
  AND token = '83dW9iaXSZjIHkmLuWwRsmSKdRv07uezgstPoLoCyzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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