SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '942b47a21385e244466cb9395669055f3ee1d71f8136ca7bdb4ad4a8aca7674d' 
  AND token = 'GqO//gtJxWcUUzyndRniJu6nNKFhGKAVAR2dukHZsRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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