SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '195c9a54dc63bf2b679c107e11a48b75cd9568807b10380bfc3c318ab4c7cc95' 
  AND token = 'IdUDLO4a9Gne56zR+gh2aDJjLN3iqY1Z/uli/t1JpwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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