SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a294111f564f7eba5fa596864a272b34925e25737e87930db5305980b6c01ae' 
  AND token = '3SbgNSnIXhFKUtCKhl1uSjbD0R/kGiC6zUfuQmZXOlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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