SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07868a42dc501499491b549049a1459aa5a627f3b3cef1b31b4f1d4bf9f51b44' 
  AND token = 'Hknoc+AokvCqJ9CkXqXd34NTNhPNzi2GojWACb07gGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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