SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3066b590a789cfad05baf44638312b4a3096ffbb9c3f82508d57063b5973fca5' 
  AND token = 'uiW79Zjy2DGp4UDJDmbz714mIqR3HSrLaWHTQqbfPZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00112

JSON explain

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