SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '472332ddd00da6c83d45e9c553947520cfbdab2d090e3fa2d6c81550e2b43401' 
  AND token = 'jb9wAWkmKag6vv3cmixLsbFmcSNVNbzepA7Bdyv/Xnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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