SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe54411d3b3546abc54b4fdd7e6e636084700662312ce606604bc5ca7e25d3b7' 
  AND token = 'xt6S3YcK7ZogWzVjORfS/IviVoaukyXyliL/fZedNGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}