SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61f9a3777cdadbe664c6bd79aa2fcedd6764c7a3a724eea6746fd8daea4022ba' 
  AND token = 'vjh/FB41txx5ULXvXRKCvwj46BejFMpNdQw9OHWEc20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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