SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45efbd98e7258b19792a9af4d62c5e11ec02c3d1786cfd2e44c5a1e173f8507a' 
  AND token = 'Z7Idji6FBCV45uRSJFzHDw+sQYpX2Gl+NpGRRP2el/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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