SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbb30e7e4d43e2bae1102d1ccd46d5a976fb745853d257782bce4d9082362a0a' 
  AND token = '+f43JXF0Ffbs808vVu9pgD0k3HQb7C3+UpDScQEEuI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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