SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08f7058fce4355a495aa6f035e7494ac3690bc063d181a136d6024a81cffee1c' 
  AND token = 'pah6dqQshABrDVa1hO59ZbR69ZKWTqXK8552sHOfavA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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