SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17c9d482b52acea18cb5b752bc8ba4f63a8f56317f3641f9541bf3949e153e87' 
  AND token = 'fAeGeWyzYIu1hLA+DVwR5d2B49tbM9NTSBaqHOMrGo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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