SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9012262c276479cf79623373b486072db175b18481a52bc66fde7f0e1dfb07da' 
  AND token = 'qXkPUNcslhYWYCK53ejh8twgVvVDrVLtNbWyST+04Ls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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