SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e550341254dc45a82239ef7ce98712bb4f0e04c8f911ce582dc4227ed5f76d4c' 
  AND token = 'bRCGxghv261dTIPogX8TDVMASKUqfWk0oO0rZHofedw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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