SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c67570eff571750a06545c68dee48fdc23951432120b1392840a13add8ed81b' 
  AND token = 'Y5M12NiYQCPGHAiLiBL4oEqRBJnWdO27hhkY1kfeLSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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