SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8156f6645751dc1550ebbbe57e725b7a4482fff0c1d9faf16f0c9f02de70dfa4' 
  AND token = 'aUEtPeK77QzrAWYu/F1Nh3h8SxAYexNvJRuVIGgS91U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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