SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e14e81a6ec7c529676a60ce1b30097527bdf9e5ff1701eb7d5d5010dbbab1814' 
  AND token = 'uRnvFDIC+tWsHK8bhCG6dLGFmZXqhvCH8rRcDJv2okc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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