SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4096fa597d6a187cb2dcd891df08125a11befbf2bdabb7770ac33f67d3c27254' 
  AND token = 'syn6nZQDFP8t1t57YLQlpPMQqwcecpajOArKi98l/+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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