SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96beec6969e66e8fe5f17027f1179ad981ca4a9a53faba569f2e4a6f2c626b83' 
  AND token = 'lhE0kw6v3mz5nwyysJq8M3abRz2QEfjTD1Mh8SmaZyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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