SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '918e7e6d07b88ccaec261841810c2ed19e6427e9f059c7bf6756c47467bc68fc' 
  AND token = 'AkufiOTQ8TYr9WGLbprlgcP9NXJGc6SveaNwJUr/KQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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