SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c222bcee62940b6027ac132a082d7b63a14f0166aed20070b216d0606ece9788' 
  AND token = '2OcziG/AZUUWnfMSO0P3zBioekoftsUIeiFClZG1EO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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