SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f82fc6a133c9f2f1b3efec1daeb9ac833a82042cbdf58abdc282eeab115618e0' 
  AND token = 'RmfecoaFjgfGzxFDULincyPd3PjelHN6WftAxEE4zBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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