SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5be264060eb3a8d52c90cf3e9a990f23db8f8091f8d80740ff395c0a5c85d0f' 
  AND token = '1VgoIbPHMM/1b0ZD3iI2lBsHPBhZRWUHFEVtkhn1P2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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