SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51e296fadd14bcc8374ac1d39c1224aef3167772eb4757759d43c3d427a85733' 
  AND token = 'mzpE+J/ZAPRLUhHlvlwKxSEb0/EHoWpMDY57ruQoX7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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