SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '662fec1cae8b05376bb66c2b70cd63e38fae75bafdc333f27108a6850ecb420f' 
  AND token = 'KSyn9POeHOQAUruoQ2SEgCsUWu1NCGSNzoBhkG+vGZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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