SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b118f4e499468228db35e4b8a5e3c8623572506cc480b7ad6a776f7316c3560c' 
  AND token = 'T1hnVMS8fRRJU5MbBwlWSLYfF9AMbSzwm+VuR3vVsJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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