SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deefb30d866ff219234a3c6994a3d55ed66d20ed9c47c926fb1dc92928339925' 
  AND token = 'p3McVIh1jnqQyrOAwAaGuKH8RkmsMCGrULbWQdCcrVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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