SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13bfa8d31ee4c4aa1c94d536912801126a3650bfc99c6f8b5da81696f5038878' 
  AND token = 'LgzEfymR3LYlcRTRcQ9FIP4UUOwstS/JoMV19pZtOOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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