SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf3567c353289588019dd8bf5efe58d0a311ebabc351f2d772fe3a4334d62c8c' 
  AND token = '0gEB3PC6H4uAGlsHJTZo68eqi+bXPvbmTmKXv2EGaaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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