SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79640a93626e4416dc62d96fe4e2c468cca85f162f9bd53a54a8f71c41dc033c' 
  AND token = 'G4Or2Y9qGygiUJTBYza+0gg9wkS/yL5+gwnXsAZLP0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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