SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36894882b4b873936d1ba788f5f88e3a71999b9a5cedde20c1c20f2c5304bce0' 
  AND token = '/JrjzP6fzo9GSkiih8cQnRVI2PnnaqYBew5pWQ3CU3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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