SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c55ea07916a3040cca2a510cadce751a8733663c052fe3777d2adb25f0253219' 
  AND token = 'Rq/eeKf/Hr5NV0wvkIEsJW/14QyMlElvnBxIyH/UYkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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