SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93184bc080990f4047420ea923f74c9a4fa29ea2adb057ec5aca42fd24ffdc49' 
  AND token = 'IN72kGLOPnGE2zU4NrPmTgR2MDvfBpbuNDuaCj35P0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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