SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f73eeaa1a6064424447b4eadfaa7cfc0f74c4f96529baaf48a548069aa6f4187' 
  AND token = 'Z/Ci5mVfr+Ms+IWlfGm2dAB2R1wIchWphDhKtJg3zRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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