SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5659d99160f8b9c62f581816b4d40b3aea22893f977f38374528b59e0be71de7' 
  AND token = 'Mswz/yljT9AWBMYZqhFng4UT00MBxfF4Bha03R9CqX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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