SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eeeb049a1a06527bf4a2a8bf03b90b0a30eeddc04887c23dd1afac563d0191a' 
  AND token = 'RnzuIbKZBCst31g8kEopLlYZdhIiFzmbqRVHKqXB6kI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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