SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bf65bbdc19ac55884814c58c1cc8040ec5218457e8056824686f762657d4224' 
  AND token = 'TUeASviR/s25dtzIxDTCyjBBo/nzwwpdjRAouIlpbLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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