SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48e40689b89ba2feeac7bb65cf85d63540006813903475abcfd982c5b42caa0a' 
  AND token = 'fAfaIcloWTGWTPfYoB2+tNDw1NhNITdHlIOc+d1FGU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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