SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4598bebbe3ff66cb634605e87e5fe13d588737230a2b4760d97b99760bdadf0f' 
  AND token = '1xUONVrTZ/zVNZOZWbOrOPxksfXBa3DDL5Yr1R5/6N8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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