SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '245d8c289b29d85f5f06f1f8abab71dfa472bbbdb7ad9b679db7ffdf3d6adc23' 
  AND token = 'nulijSvgkJdWXy6Sf6kbtSKlilbsCTc45jLcIj3LCLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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