SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7bf0f567bcfbabc96c173b315967412e9cbc9db41808c8d13896bf0a9787140' 
  AND token = 'P9edHpTTrQ925RT5AnOP9EkDT1TI1moyH4I07dzYMZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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