SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1bca21ae6354b07099f3b7d4fe76f427897b219828f666e90f6888803461ffd' 
  AND token = 'Eq3aM3GighMFkBQg1wXwFHhXoEIAYEr5BcYv9VvCrzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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