SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3505abd2bbf5f0b9e5a7d4e15e0c52d89ed1ba4e620ca79703ec1e2e169ee512' 
  AND token = 'zzVBKEuZVQgU3yEAjBHurfF4z5YG/vwFh+Jt+Gl4SCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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