SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b82ae4cdbd283fde6fe94b306b444d4d76586668a1e46a8fd82fbde335aefbd3' 
  AND token = 'dg4G5xmaIyhAGgfaaNh1nesf6JGwyI9hPMBNN5V80+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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