SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9aefc2d696a32e91e06b86a79d51064bf851e18e5b02d31fe367f7290097f1ec' 
  AND token = 'Vk4OM5JtywV+CcvRjDDnkVyBJK7fzkYS+v2XWSuPhlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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